To get an instance of Onbase, you will need to submit a ticket via the service portal. 

On the IT site: https://it.stonybrook.edu/services/itsm click Create a Service Ticket
1. If prompted select Stony Brook University (not Stony Brook Medicine)
2. Select Make a Request
3. Select Administrative Software and Applications
4. Select Document Management
5. Select OnBase
6. Select New/Edit Role

And follow the instructions provided to submit a request through the self-service portal